Brief CPU spikes can disappear before Task Manager is opened. Performance Monitor (PerfMon) in Windows displays CPU usage as a live graph and can save samples for later inspection.

The _Total instance averages activity across the logical processors. A low total can therefore hide one busy logical processor, while sustained high total usage means little processing capacity is left for other applications. CPU utilization does not measure temperature or identify the application responsible for the load.

The live graph is temporary. A Data Collector Set keeps CPU samples in a binary .blg log, which remains available under Reports after collection stops. Recording system counters may require administrator permission.

Related: How to monitor CPU usage in Windows using Resource Monitor
Related: How to troubleshoot high CPU usage on Windows

Steps to monitor CPU usage with Performance Monitor (PerfMon):

  1. Launch Performance Monitor from Run (Win + R) with perfmon.

    If Windows denies permission to create or start a collector, Run as administrator is available for Performance Monitor in Start search.

  2. Select Monitoring Tools → Performance Monitor in the left pane.
  3. Confirm the live graph updates with % Processor Time for the _Total instance.

    The default counter may appear under Processor Information or Processor. Last is the latest percentage; Average, Minimum, and Maximum describe the displayed time range.

  4. Expand Data Collector Sets in the left pane.
  5. Choose New → Data Collector Set from the User Defined right-click menu.
  6. Enter CPU Usage in the Name field.
  7. Select Create manually (Advanced).
  8. Click Next to choose the data to record.
  9. Check Performance counter under Create data logs.
  10. Click Next to choose performance counters.
  11. Click Add… beside the empty Performance counters list.
  12. Expand Processor in the available counters list for <Local computer>.
  13. Select % Processor Time under Processor.
  14. Select _Total under Instances of selected object.

    _Total records overall CPU usage; numbered instances such as 0 and 1 represent individual logical processors.

  15. Click Add » to include the selected CPU counter.
  16. Click OK with % Processor Time and _Total listed under Added counters.
  17. Set Sample interval to 5 seconds.

    A five-second interval suits a short troubleshooting capture. Longer intervals reduce the number of samples but can smooth out brief spikes.

  18. Click Next with Units set to Seconds.
  19. Click Next to keep the default Root directory.

    The default is %systemdrive%\PerfLogs\Admin\CPU Usage, normally under C:\PerfLogs. The wizard creates a separate subfolder for each recording.

  20. Click Finish to save the CPU Usage collector.

    The default Save and close selection leaves recording stopped. If the console closes after saving, the set remains under Data Collector Sets → User Defined when perfmon is reopened.

    Collection continues until stopped and consumes disk space. A full system drive can disrupt Windows; keep the capture limited to the period needed.

  21. Choose Start from the CPU Usage right-click menu under Data Collector Sets → User Defined.
  22. Confirm CPU Usage shows Running in the User Defined list.

    The collector records in the background while the activity being investigated takes place.

  23. Choose Stop from the CPU Usage right-click menu after the capture period.
  24. Open the CPU Usage report folder under Reports → User Defined.
  25. Open the newest recorded run under CPU Usage.

    Each run name includes the computer name and date. The Date column identifies the capture time.

  26. Select % Processor Time below the recorded graph.
  27. Confirm the _Total counter shows a recorded graph and numeric Average, Minimum, and Maximum values.

    The time labels identify the captured period. A blank graph or dashed statistics does not show usable CPU history.

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